1. Field of the Invention
The present invention relates generally to overhead doors and, more particularly, to brackets for retaining rollers for a top panel in an overhead door.
2. Description of the Prior Art
Overhead doors are well known. Especially common are sectional, roll up doors that employ a pair of tracks for rollers. Each track has a vertical portion for retaining door panels in a vertical or closed orientation (door "down"), and each track has a horizontal portion for retaining door panels in a horizontal or open orientation (door "up"). In the area of overhead doors, the concept of headroom relates to the space above a closed door that is required for retaining the horizontal portions of the tracks. Moreover, the headroom space retains the overhead door when the overhead door is in an open or horizontal orientation. For optimum action, many conventional overhead doors require a headroom space that has a height of twelve inches. However, due to construction of a structure, such as a garage, often less than a standard height of twelve inches is allowed for the headroom space.
When less than twelve inches of headroom space are provided, several alternatives are known. One such alternative is the provision of what are known as low headroom tracks which require only six inches height for headroom space. However, such low headroom tracks are expensive and excessively time consuming to install. In this respect, it would be desirable if a device were provided for an overhead door that does not use low headroom tracks.
Another alternative to having a twelve inch height for a headroom space is to cut several inches from the bottom of the vertical portions of the roller tracks. In this way, the horizontal portions of the tracks would be lowered. When this is done, known substitute top brackets need to be installed at the two top corners of the door. Such known substitute top brackets are disclosed in U.S. Pat. No. 4,095,641 and may not perform as well as intended. In this respect, it would be desirable if a device were provided for an overhead door that does not employ known top brackets that are employed with overhead doors for which several inches have been cut from the bottoms of vertical portions of the roller tracks.
As discussed above, provisions are made in the prior art for a vertical height of headroom space to be in a range of six to twelve inches. However, there are applications that may call for a vertical height of headroom space to be less than six inches. In this respect, it would be desirable if a device were provided for an overhead door that permits a vertical height for headroom space to be less than six inches. Moreover, there may also be applications in which it would be desirable for the vertical height of headroom space to be no higher than the vertical distance required by the horizontal portions of roller tracks.
Aside from U.S. Pat. No. 4,095,641 mentioned above, throughout the years, a number of innovations have been developed relating to overhead doors, and the following U.S. patents are representative of some of those innovations: U.S. Pat. Nos. 4,878,529, 5,042,556, 5,135,040, 5,235,724, and Des. 337,042. More specifically, U.S. Pat. No. 4,878,529 discloses an overhead door that has door-pulling gear located above the horizontal portions of roller tracks. Consequently, a relatively large vertical height is needed for the headroom space. In this respect, it would be desirable if a device were provided for an overhead door that does not include door-pulling gear located above the horizontal portions of roller tracks.
Each of U.S. Pat. Nos. 5,042,556 and 5,135,040 discloses an overhead door that includes a pair of stationary corner wheels that change vertical to horizontal motion for the door panels. It would be desirable to avoid the installation and the expense of such direction-changing stationary corner wheels. In this respect, it would be desirable if a device were provided for an overhead door that avoids the use of stationary, direction-changing corner wheels.
U.S. Pat. No. 5,235,724 may be of interest for its disclosure of a roller-hinge assembly for a retractable overhead door. U.S. Pat. No. Des. 337,042 may be of interest for its disclosure of an angled bracket for overhead garage doors.
Thus, while the foregoing body of prior art indicates it to be well known to use overhead doors with headroom spaces whose vertical height is less than twelve inches, the prior art described above does not teach or suggest a roller bracket apparatus for an overhead door which has the following combination of desirable features: (1) does not use low headroom tracks; (2) does not employ known top brackets that are employed with overhead doors for which several inches have been cut from the bottoms of vertical portions of the roller tracks; (3) permits a vertical height for headroom space to be less than six inches; (4) permits the vertical height of headroom space to be no higher than the vertical distance required by the horizontal portions of roller tracks; (5) does not include door-pulling gear located above the horizontal portions of roller tracks; and (6) avoids the use of stationary, direction-changing corner wheels. The foregoing desired characteristics are provided by the unique roller bracket apparatus for an overhead door of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.